Fuse



W. T. MOORE FUSE Filed Jan. 29, 1940 lT'LvETLtUF i193 T Mum E AtLEIY'TLE 5 Patented Oct. 10, 1944 UNITED SATES ENT OFECE (Granted under the act of March s, 1883, as amended April 30, 1928; 370 0. G. 757) 2 Claims.

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to an explosive projectile or fuse.

Fuses have been arranged with safety devices which restrain the firing pin from engagement with the primer until after the fuse has been subjected to acceleration or rotation. Both of these methods arm the fuse in the gunbarrel or near the muzzle and provide a condition which is dangerous for synchronized guns firing through the propeller blades and for field guns firing through underbrush, trees or camouflage.

The principal object of this invention is to provide a fuse which will insure delayed arming and which will produce this result by means of a combustible barrier which is removed without regard to acceleration or rotational forces.

Other objects of the invention are to provide a compact and readily assembled fuse which is adapted for a relatively small projectile and which may include a self-destroying feature when the projectile is to be used over friendly territory.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of an embodiment as shown in the accompanying drawing, in which:

Fig. 1 is a longitudinal sectional view of a projectile constructed in accordance with the invention.

Fig. 2 is a sectional view on the line 2-2 of Fig, .1.

Referring to the drawing by characters of reference there is shown a projectile comprising a body, shell or a jacket 5 which in the case of a smaller caliber projectile preferably consists of gilding metal so as to be capable of being engraved by the rifiing of a gun barrel. The jacket is formed with a closed front end 6 and with an open base 1 through which an explosive charge 8 may be loaded.

The explosive charge extends rearwardly of the center of the jacket and terminates at an annular shoulder 9 which is formed by an enlarged internal diameter. The wall of the jacket is of substantially uniform thickness forwardly of the shoulder 9 and of reduced uniform thickness rearwardly thereof.

A support or plug 10, preferably of brass, is inserted through the rear end of the jacket and is moved into engagement with the annular shoulder 9 by which it is firmly supported so that it will take the load of compression during assembling of the various elements as Well as the pressure of the propelling charge when the projectile is fired. The plug has a close fit with the jacket in order to prevent by-passing of flame or hot propelling charge gases to the explosive charge. The plug also serves as a heat bafile.

The plug is provided with a central passage H which communicates with an enlarged recess I2 formed in the front face of the plug and receiving a cup l3 carrying a priming charge L The plug is also provided with one or more longitudinal passages each containing a delay powder train IS in its rear portion and a detonating element 16 in its front portion.

The firing pin comprises a stem l1 partially inserted in the central passage ll of the plug and guided thereby, and an, enlarged head l8 disposed in rear of the plug. As an illustration the head I8 is of the hobnail type having a large base 19 and a conical side 20 with flutes 2|. The base of the jacket is turned in towards the conical side 20 of the head and restrains it against rearward displacement while permitting entrance into the jacket of the hot gases of the propellent charge.

The firing pin is normally maintained in the safe or unarmed position by means of a barrier of a combustible material 22 which may consist of compressed meal powder, tracer composition, or any suitable material which burns to a gas without forming excessive amounts of hard slag. The combustible barrier is capable of being ignited by the hot gases of the propelling charge and it should be of such quantity that it will only be consumed after the projectile has traveled a safe distance from the gun, for example the time of combustion should correspond to a travel of from to 200 feet. The combustible material 22 may be provided with a preformed aperture for receiving the stem of the firing pin and it is conveniently loaded into the jacket prior to insertion of the firing pin. Pressure may be applied to it to insure a close fit with the jacket and to eliminate cracks and fissures. During such operation the pressure is transmitted by the plug H) and taken by the shoulder 9 of the jacket. The combustible barrier then serves as a seal to prevent the hot gases from the propelling charge from passing directly to the explosive elements l4 and Hi.

The head of the firing pin may assume other forms so long as they meet the requirements of cooperation with the combustible barrier and provision for entry of the gases of the propellent charge. In the case of the conical head illustrated in the drawing there is an annular space 23 between the head and the base I of the jacket and this space as well as the flutes may be conveniently filled with an ignition charge 24 which may be of the same material as the combustible barrier 22.

In the safe or unarmed condition of the projectile the parts are in the positions shown in the drawing. When the projectile is fired the gases from the propelling charge ignite the barrier 22 while the barrier initially prevents relative forward movement of the firing pin. Should the projectile encounter an obstacle before the barrier is substantially completelyconsumed the leading to the said primer, a firing pin comprising a pointed stem traversable in the said passage and an enlarged head having a shoulder and tapered therefrom towards the base of the projectile, a barrier of combustible material in the base of the projectile embedding the said firing 'pin head and cooperatingwith its said shoulder to maintain its said pointed stem from the said primer, the said projectile base having a central opening seating the apex portion of the said ta- ---pered head to center the firing pin, the said tapered head being fluted to permit ingress of the propellant gases through the said central base opening, the said tapered formation of the head providing "an enlarged mass of the combustible materialnear the base of the projectile for initial ignition and a reduced annular mass at the said shoulder oft-he firing pin head for slower uniform combustion of the said barrier.

-2. The combination according to claim -1 further provided with a plug separating the said combustible barrier from-the explosive charge in the nose of the projectile, the said plug having a plurality of cores, detonating means at the ends of the said cores facing the explosive charge, the said cores being filled with sloW-burning -powder adapted to be ignited by the said combustible ma terial in the base of the projectile V p p H WILEY T. MOORE. 

